This spam filter started life as an entry at VMware.
It was done by Redbudcomputers,
obviously a talented bunch.

Since VMWare
server is a free product, Castellan
decided to setup a virtual machine that will block spam, and offer it s a freebie.

The appliance from Redbud was very similar to our own spam filter, but with
a much easier configuration script - the redbud appliance only takes about 5
minutes to setup. Castellan has modified
this spam filter based on our production experience, and presents it as a free
download. It will do ldap integration with active directory, so it is the ideal
filter for exchange 2000/2003/2007 installations.

A bunch of these on cheap celeron boxes makes a great MX farm (3 Dell Dimension
Workstations for $1000), giving you plenty of redundancy for safely accepting
incoming email.

The only 3 Windows OS that work well with VMWare server
(and all the others we deploy) seem to be Win2K3 Server, Win2K Server (sp4),
or WinXP Pro (not home) SP2. Everything else seems to crash & have network
problems.

postfix is configured using all the best tips and tricks, including ones
from the famous postfix
anti-uce site among others

a large number of additional rules for spamassassin are now available if
chosen during the install (rules_du_jour)

instead of using a list of RBLs, policyd-weight
is installed to weight a full list of RBLs for each incoming connection

antivirus is enabled by default - it is a safety issue, even though it causes
a small performance penalty - you can disable AV in the file /usr/local/etc/amavisd.conf
by un-commenting a single line

memory usage upped to 512mb

https://{machine ip}
will take you to a reference page with admin links for the virtual appliance,
and all the original documentation that came with the appliance

a windows program that acts as your GUI to add email addresses, email domains,
or IP addresses to the whitelist & blacklist files in the spam filter

This actual VM is in use at several Castellan Client sites, and it is working
very well. Easily blocking 90% (95%+ with the Exchange
IMF) of spam at this point (if you install the appliance with a setting
of 6.31), with a 5 minute configuration. There is a lot of administrator-level
documentation included in the appliance. Please take time
to read all the docs, and investigate EACH LINK from the index.html page of
the appliance.

A typical install in an Active Directory/Exchange environment
would be similar to: create a DNS entry for the appliance in DNS; create a user
in active directory for LDAP lookups on the appliance; install VMWare; unzip
the appliance; read the DOCs; run appliance and follow script instructions,
if ldap lookups fail, then setup the ldap vbscript to push email addys to appliance.

Download location - 682MB zip file (you may have
to click a couple of times to get it to download)Blacklist/Whitelist Editor - this is the current build
for just the editor itself - under 200kb - there are many
bugfixes in this buildDot
Net 2 - this is required to run the blacklist editor

Read all the docs, and look at the source for
each script. That is the real cost of a free enterprise spam filter - you need
to spend 2 hours of time going thru all the docs before even thinking of trying
to implement in production.